A very large number of solder compositions are known. In particular, solders containing lead and tin or containing indium and tin have long been in common usage. Most solders comprise mixtures of heavy metals such as lead, indium, and tin. Other heavy metals such as bismuth, antimony, gold, silver, cadmium, zinc, gallium mercury, copper, and nickel may also be found in some solder compositions.
Boehm, et al. in U.S. Pat. No. 4,797,328 disclose a soft solder alloy for connecting ceramic parts which soft solder comprises 86 to 99% lead or tin, 0 to 13% silver and/or copper, 0 to 10% indium, and 1 to 10% titanium and/or zirconium.
Szulczyk, et al., in U.S. Pat. No. 4,344,794, disclose a solder for non-noble metal containing silver contacts, which solder consists of a silver-copper alloy with cadmium and/or tin and/or indium.
Lithium has been used as a grain-refining element in some non-solder alloys. Schaffer, et al., in U.S. Pat. No. 4,917,861 teach the use of lithium in palladium dental restoration alloys for this grain-refining purpose.
Eagar, et al., in U.S. Pat. No. 4,810,308 teach the use of lithium together with silver and copper and either tin or antimony as well as other elements to make a hardenable silver alloy.
Turowski, in U.S. Pat. No. 3,881,953 teaches the use of lead, calcium, lithium, tin alloys as battery electrode grids, said alloys consisting essentially of about 0.05-0.07 percent lithium, 0.005-0.15 percent calcium, 0.1-2 percent tin, by weight and the balance lead.
None of these patents, however, discloses the use of the reactive light metal elements lithium, sodium, potassium, rubidium, cesium, calcium, and magnesium or the alloys magnesium-lithium, and calcium-lithium to improve the properties of solders, especially the ability of the heavy metal solder to wet and to adhere hermetically to glass.